Keratosis Pilaris or 'Chicken Skin'

Could That Sandpapery Skin Rash Be Keratosis Pilaris?

Cropped shot of young woman scratching her forearm with fingers
What is keratosis pilaris (chicken skin,) why does it occur, and how is it treated?. Maria Fuchs/Cultura/Getty

What is keratosis pilaris? What causes this condition, how long does it last, and how should it be treated?

Keratosis Pilaris (Chicken Skin)—Definition

Keratosis pilaris is a skin condition that occurs most commonly on the upper arms in children. It is commonly referred to as "chicken skin" based on the sandpapery feel of the rash which is often flesh colored. As a commonly inherited rash present in the majority of children at some time, it often resolves as children pass to adulthood without any specific treatment.

Keratosis Pilaris—Appearance and Symptoms

Keratosis pilaris is a rash composed of rough, dry, skin-colored bumps on the extensor (outer) surfaces of the upper arms, thighs, and buttocks which occurs most commonly in childhood, but may occur at other times as well (see below.) The rash is not usually red or inflamed, but may be surrounded by some redness. The rash often has the texture of course sandpaper.

It is referred to as "chicken skin" based on its resemblance to the skin of a chicken after its feathers are plucked. It often resembles gooseflesh or "goose bumps."

The "bumps" are papules, skin lesions that are solid and can't be squeezed, in contrast to pustules or "white heads." They do not drain (but can hurt!) when squeezed or scraped.

Symptoms of Keratosis Pilaris

Other than a sandpaper-like texture to the skin, keratosis pilaris has few symptoms. It does not usually itch, and if there is itching it is usually mild.

It is the appearance of the rash (cosmetic reasons) that prompts most people to seek medical attention.

What Causes

Keratosis occurs as a result of problems in the normal keratinization of the skin resulting in an abnormal buildup of the skin protein keratin. This keratin forms plugs in the hair follicles giving rise to its appearance.

Under the microscope you can see plugs of keratin in the hair follicles surrounded by redness.

Risk Factors for Keratosis Pilaris

Keratosis pilaris occurs most commonly in children and appears to be hereditary in nature. It seems to be related to allergic diseases and atopic dermatitis (ezcema) but may also occur in people without allergies.

Keratotis pilaris has been reported in adults following pregnancy, and more recently has been seen in people who have been treated with targeted therapies for cancer such as Tarceva (erlotinib.)

Associated Conditions—What Other Skin Disorders May Occur with Keratotis Pilaris

As noted earlier, keratosis pilaris is found more often in people with allergies and allergic skin conditions such as eczema. It may also be found with other skin conditions such as icthyosis vulgaris (fish skin,) erythromelanosis follicularis faiei et colli, and keratosis pilaris atrophicans.

On the other end of the spectrum, keratosis pilaris is seen less often than usual in people with acne.

How is Keratosis Pilaris Differentiated from Eczema?

Eczema, or atopic dermatitis is an itch that, when scratched, turns into a rash. Therefore, for a rash to be eczema, it is usually itchy and scratched before the rash develops.

In contrast, keratosis pilaris does not itch and appears before any scratching takes place.

Treatment of Keratosis Pilaris

In general, the rash of keratosis pilaris does not require any treatment, and will usually go away as a child ages or when whatever stressor (pregnancy, cancer treatment) brought on the rash is done.

That said, some people are concerned about the cosmetic appearance of the rash, and there are a number of treatments which may improve the appearance of the rash.

Over the counter moisturizing creams or exfoliants may help. Other treatments (available by prescription) which have been found helpful include LacHydrin cream, topical steroids, as well as topical retinoids (such as Retin-A (tretinoin.))

If these treatments are not effective, laser (pulsed dye laser) therapy is effective. Photopneumatic therapy is also being evaluated.

While little research has been done, some people feel that food allergies may play some role in the development of keratosis pilaris, and those who are interested may wish to try an elimination diet to evaluate this possibility.

Coping with Keratosis Pilaris

Several "non-medication" approaches may help improve the appearance of keratosis pilaris as well. These include:

  • Avoiding scratching or picking at the rash
  • Avoiding hot water showers (using lukewarm water instead)
  • Using a moisturizer regularly
  • Increasing the humidity in your home

Prognosis of Keratosis Pilaris

Keratosis pilaris usually goes away as a child ages or whenever the situation which led to the rash resolves. Unlike some skin rashes, it is rare that a secondary infection would develop and scarring does not usually occur.

Bottom Line on Keratosis Pilaris

Keratosis pilaris is a rash which is often hereditary and occurs most commonly in children. The rash itself is not dangerous and usually goes away on its own. If the rash is distressing due to its cosmetic appearance, there are a number of lifestyle and medical approaches which can improve the appearance of the rash.

Sources:

Hwang, S., and R. Schwartz. Keratosis Pilaris: A Common Follicular Hyperkeratosis. Cutis. 2008. 82(3):177-80.

Ibrahim, O., Khan, M., Bolotin, D. et al. Treatment of Keratosis Pilaris with 810-nm Diode Laser: A Randomized Trial. JAMA Dermatology. 2015. 151(2):187-91.

Schoch, J., Tollefson, M., Witman, P., and D. Davis. Successful Treatment of Keratosis Pilaris Rubra with Pulsed Dye Laser. Pediatric Dermatology. 2016. 33(4):443-6.

Zhu, J., Lu, Z., and M. Zheng. Unilateral Generalized Keratosis Pilaris Following Pregnancy. Cutis. 2014. 94(4):203-5.

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